A Tesla dealership is seen in West Drayton, just outside London, Britain, February 7, 2018. REUTERS/Hannah McKay

Tesla’s Semi, its first electric heavy duty truck, is “substantially” similar to Nikola’s design, Nikola Motor said in a court filing.

Salt Lake City, Utah-based Nikola claims it was issued six design patents by the U.S. Patent and Trademark Office between February and April 2018 for its wrap windshield, mid-entry door, fuselage, fender, side cladding and the overall design of the Nikola One.

“Nikola estimates its harm from Tesla’s infringement to be in excess of $2 billion,” it said in the filing.

A Tesla spokesman rejected the claims.

“It’s patently obvious there is no merit to this lawsuit,” a Tesla spokesman told Reuters in an email.

Tesla Chief Executive Elon Musk unveiled the Tesla Semi, its electric heavy duty truck, in November. The company has not given much details of the Semi, but has said that the truck would begin production in 2019.